查詢幫助 - 匹配階段並返回最近的一個

Question

下面的代碼顯示有多個候選人的學生，但不是他們當前的。學生不能在同一年，期限和部門不止一個候選人，所以這是針對他們，這樣我可以批量刪除它們。

我需要的代碼，將只針對最高階段添加。如果階段相匹配，它會採取一個與最近的日期（hist_stage_dte）。我需要幫助。不勝感激。謝謝！

SELECT * 
FROM candidacy 
WHERE (candidacy.yr_cde = '2017') AND 
    (candidacy.trm_cde = '20') AND 
    (candidacy.div_cde like 'g%') and 
    (candidacy.CUR_CANDIDACY = 'n') and 
    (candidacy.ID_NUM in (SELECT candidacy.id_num  
          FROM candidacy 
          WHERE (candidacy.yr_cde = '2017') AND 
           (candidacy.trm_cde = '20') AND 
           (candidacy.div_cde like 'g%') 
          GROUP BY candidacy.id_num 
          HAVING count(candidacy.id_num) > 1)) 

Answer 1

嘗試通過ROW_NUMBER函數拾取記錄。要在where子句中使用行號，請進行第二個子查詢。

SELECT * 
    FROM 
    (SELECT ROW_NUMBER() OVER (PARTITION BY ID_NUM ORDER BY hist_stage_dte DESC) as ROW_NUM, * 
    FROM candidacy 
    WHERE (candidacy.yr_cde = '2017') AND 
      (candidacy.trm_cde = '20') AND 
      (candidacy.div_cde like 'g%') and 
      (candidacy.CUR_CANDIDACY = 'n') and 
      (candidacy.ID_NUM in (SELECT candidacy.id_num  
           FROM candidacy 
           WHERE (candidacy.yr_cde = '2017') AND 
             (candidacy.trm_cde = '20') AND 
             (candidacy.div_cde like 'g%') 
           GROUP BY candidacy.id_num 
           HAVING count(candidacy.id_num) > 1)) 
    ) TB_AUX 
    WHERE ROW_NUM = 1 

什麼是您使用SQL服務器